Addressing sleep in a weight loss intervention: does it lead to more changes in diet, physical activity and weight loss in overweight Lebanese students?

ISRCTN	ISRCTN91057387
DOI	https://doi.org/10.1186/ISRCTN91057387
Sponsor	Lebanese International University
Funder	Investigator initiated and funded

Submission date: 20/07/2026
Registration date: 21/07/2026
Last edited: 01/09/2026

Recruitment status: Recruiting
Overall study status: Ongoing
Condition category: Nutritional, Metabolic, Endocrine

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Record updated in last year

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Ree Meertens
Principal investigator

Maastricht University
Maastricht
6211LM
Netherlands

Phone	+31 433882407
Email	r.meertens@maastrichtuniversity.nl

Mrs Mira Alfikany
Public, Scientific

Bekaa
Zahle
1801
Lebanon

ORCID ID	0009-0004-1801-9938
Phone	+961 3031209
Email	m.alfikany@maastrichtuniversity.nl

Study information

Primary study design	Interventional
Allocation	Randomized controlled trial
Masking	Open (masking not used)
Control	Active
Assignment	Parallel
Purpose	Effects of sleep improvement on weight loss outcomes and adherence to diet and exercise.
Scientific title	The effect of addressing sleep in a weight loss program on diet, exercise and weight loss in Lebanese university students: a pilot randomized controlled trial
Study objectives	1. Test if improving sleep behaviors produces positive spillover effects on weight-related behaviors, such as dietary and physical activity adherence and success. 2. Examine whether the process of striving for and achieving improvements in sleep strengthens individuals’ self-identification with healthy behaviors, notably diet and exercise, and this beyond the direct effects of diet and exercise guidance.
Ethics approval(s)	Approved 24/03/2026, Lebanese International University - Institutional review board (Beirut, Lebanon, Beirut, 146404 Mazraa, Lebanon; +961 776 76 01; hassan.khachfe@liu.edu.lb), ref: LIUIRB-260218-MA-450
Health condition(s) or problem(s) studied	Overweight and obesity
Intervention	This study will use a two-arm, parallel-group design to investigate whether improving sleep duration and quality, in parallel with a weight-loss program, leads to spillover effects on adherence and weight-loss outcomes. Participants will be randomly allocated in a 1:1 ratio to either (1) usual care (diet + exercise) or (2) sleep spillover group (usual care plus a sleep education and health identity stimulation). We aim to recruit approximately 12 participants per arm. Randomization will be done using a sealed-envelope method. An independent researcher who has no other role in intervention or assessment will prepare group assignments in advance according to a random sequence generated. Each assignment will be placed in an opaque, sealed, and sequentially numbered envelope. Upon enrollment, the study coordinator will open the next envelope in sequence to reveal group allocation. Participants will be followed for 6 months, with monthly visits conducted by a licensed nutritionist. Group 1: Usual Care (diet + exercise) Participants in this group will receive an individualized weight loss diet and exercise program without any sleep-related education or identity stimulation components. Each participant will receive: 1. An individualized dietary program aiming at losing 1-2 pounds per week (removing 500-1000 Calories per day), accompanied by educational materials to support adherence. 2. Individualized physical activity recommendations aiming to reach at least 150 min/week. 3. Guidance on cognitive-behavioral strategies to support healthy habits, including the consumption of regular meals without skipping any of the 3 main meals, eating at consistent time, avoiding excessive snacking especially evening snacking, avoiding sweet snacks and avoiding eating late at night). Group 2: Sleep spillover group + Usual Care for weight loss Participants in this group will receive a weight loss program similar to Group 1 including dietary, physical activity, and behavior modification guidance. This ensures both groups are comparable in standard care. In addition, a sleep improvement intervention, focused on increasing total sleep duration and enhancing sleep quality through behavioral and educational strategies will be administered. The sleep education will be administered by the dietitian at the initial visit along with an individualized weight loss program. Sleep education will integrate brief activities designed to stimulate healthy lifestyle identity. It will be made clear to participants that working at a better sleep quality or sleeping longer, is an important step in becoming a healthier person, and will make it easier to behave healthier in other areas as well. Each small step they take (e.g. more regular sleeping times, giving themselves more sleeping opportunity at night) will be reinforced, and used to confirm their self-identity as a person working at a healthy lifestyle. Participants will also receive positive reinforcement for small improvements in other health-related behaviors, such as choosing a healthy snack (e.g., fruit), engaging in light physical activity during the day (e.g., taking the stairs instead of the elevator or going for a short walk), or establishing regular meal times. Reinforcing these behaviors will be used to strengthen a healthy self-identity and subsequently encourage spillover to other behaviors, including sleep-related behaviors. At each contact session, positive feedback will be given to participants highlighting any successful effort (small improvements in behavior with respect to sleep, diet or physical activity), and those healthy steps will be connected to a better health, showing the participant that (s)he is the kind of individual who takes care of his health, which facilitates a potential spillover of behavior change from one health behavior to another.
Intervention type	Behavioural
Primary outcome measure(s)	Adherence to exercise measured using International Physical Activity Questionnaire (IPAQ)- Short Arabic version at monthly for 6 months Adherence to dietary recommendations measured using 24-hour recall at monthly for 6 months Exercise identity measured using the Four-item exercise identity scale (4-EI) at baseline, 3 months and 6 months Eating identity measured using four-item healthy-eater identity scale (4-HEI) at baseline, 3 months and 6 months Health identity measured using health identity scale at baseline, 3 months and 6 months Weight (kg) measured using calibrated scale at monthly for 6 months Feasibility measured using sleep hygiene index at baseline, 3 months and 6 months
Key secondary outcome measure(s)	Body composition changes (fat mass and muscle mass) measured using bioelectrical impedance machine (BOCA X1) at monthly for 6 months Waist circumference (cm) measured using flexible non-stretchable tape at monthly for 6 months
Completion date	01/03/2027

Eligibility

Participant type(s)
Age group	Mixed
Lower age limit	18 Years
Upper age limit	100 Years
Sex	All
Target sample size at registration	24
Key inclusion criteria	1. Participants should be overweight or obese (BMI≥ 25 kg/m²) 2. Participants should have a short sleep duration (< 7 hours per night) and/or a poor sleep quality (PSQI score > 5) (The validated Arabic version of the PSQI will be used to assess eligibility) 3. Participants should be healthy, not suffering from any metabolic or other chronic diseases
Key exclusion criteria	1. Students diagnosed or being treated for insomnia, obstructive sleep apnea (OSA), other sleep disorders or any other medical condition that may affect negatively the weight loss like endocrine problems (hypothyroidism…) 2. Students having any medical contraindication to weight loss 3. Students taking any medication known to affect body weight 4. Students taking any medication known to affect sleep 5. Students who are already engaged in another weight loss program or who were recently losing weight (> 5% in the past 3 months) 6. Pregnant/planning to become pregnant in the next 6 months, or breastfeeding 7. Students who smoke waterpipe as this has been found in a previous study to affect weight loss
Date of first enrolment	10/10/2026
Date of final enrolment	10/11/2026

Locations

Countries of recruitment

Lebanon

Study participating centres

Results and Publications

Individual participant data (IPD) Intention to share	Yes
IPD sharing plan	The datasets generated during and/or analyzed during the current study will be available upon request from Mira Alfikany (m.alfikany@maastrichtuniversity.nl)

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Statistical Analysis Plan			22/07/2026	No	No

Additional files

ISRCTN91057387 SAP.pdf: Statistical Analysis Plan

Editorial Notes

01/09/2026: The following changes were made to the study record:
1. The date of first enrolment was changed from 03/08/2026 to 10/10/2026.
2. The date of final enrolment was changed from 28/08/2026 to 10/11/2026.
22/07/2026: The statistical analysis plan was uploaded as an additional file.
21/07/2026: Trial's existence confirmed by Lebanese International University- Institutional review board.